An image sensor is an electronic device that can be used to capture an optical image. Image sensors are commonly found in digital cameras and other imaging devices. Modern image sensors can be broadly grouped into two broad classifications based on the type of detection unit used: charge-coupled devices (CCD) or complementary metal-oxide semiconductor (CMOS) active pixel sensors. However, other types of image sensors are also known to exist.
Generally, image sensors comprise photo sensors capable of capturing light (e.g., photons) impinging on a detection element and converting the photons into electrical signals. Subsequently, additional circuitry may convert the electrical signals into image data.